2 * Virtual network driver for conversing with remote driver backends.
4 * Copyright (c) 2002-2005, K A Fraser
5 * Copyright (c) 2005, XenSource Ltd
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version 2
9 * as published by the Free Software Foundation; or, when distributed
10 * separately from the Linux kernel or incorporated into other
11 * software packages, subject to the following license:
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34 #include <linux/module.h>
35 #include <linux/kernel.h>
36 #include <linux/netdevice.h>
37 #include <linux/etherdevice.h>
38 #include <linux/skbuff.h>
39 #include <linux/ethtool.h>
40 #include <linux/if_ether.h>
42 #include <linux/udp.h>
43 #include <linux/moduleparam.h>
45 #include <linux/slab.h>
49 #include <xen/xenbus.h>
50 #include <xen/events.h>
52 #include <xen/platform_pci.h>
53 #include <xen/grant_table.h>
55 #include <xen/interface/io/netif.h>
56 #include <xen/interface/memory.h>
57 #include <xen/interface/grant_table.h>
59 /* Module parameters */
60 static unsigned int xennet_max_queues;
61 module_param_named(max_queues, xennet_max_queues, uint, 0644);
62 MODULE_PARM_DESC(max_queues,
63 "Maximum number of queues per virtual interface");
65 #define XENNET_TIMEOUT (5 * HZ)
67 static const struct ethtool_ops xennet_ethtool_ops;
73 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
75 #define RX_COPY_THRESHOLD 256
77 #define GRANT_INVALID_REF 0
79 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
80 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
82 /* Minimum number of Rx slots (includes slot for GSO metadata). */
83 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
85 /* Queue name is interface name with "-qNNN" appended */
86 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
88 /* IRQ name is queue name with "-tx" or "-rx" appended */
89 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
91 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
93 struct netfront_stats {
96 struct u64_stats_sync syncp;
101 struct netfront_queue {
102 unsigned int id; /* Queue ID, 0-based */
103 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
104 struct netfront_info *info;
106 struct napi_struct napi;
108 /* Split event channels support, tx_* == rx_* when using
109 * single event channel.
111 unsigned int tx_evtchn, rx_evtchn;
112 unsigned int tx_irq, rx_irq;
113 /* Only used when split event channels support is enabled */
114 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
115 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
118 struct xen_netif_tx_front_ring tx;
122 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
123 * are linked from tx_skb_freelist through tx_link.
125 struct sk_buff *tx_skbs[NET_TX_RING_SIZE];
126 unsigned short tx_link[NET_TX_RING_SIZE];
127 #define TX_LINK_NONE 0xffff
128 #define TX_PENDING 0xfffe
129 grant_ref_t gref_tx_head;
130 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
131 struct page *grant_tx_page[NET_TX_RING_SIZE];
132 unsigned tx_skb_freelist;
133 unsigned int tx_pend_queue;
135 spinlock_t rx_lock ____cacheline_aligned_in_smp;
136 struct xen_netif_rx_front_ring rx;
139 struct timer_list rx_refill_timer;
141 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
142 grant_ref_t gref_rx_head;
143 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
145 unsigned int rx_rsp_unconsumed;
146 spinlock_t rx_cons_lock;
149 struct netfront_info {
150 struct list_head list;
151 struct net_device *netdev;
153 struct xenbus_device *xbdev;
155 /* Multi-queue support */
156 struct netfront_queue *queues;
159 struct netfront_stats __percpu *rx_stats;
160 struct netfront_stats __percpu *tx_stats;
162 /* Is device behaving sane? */
165 atomic_t rx_gso_checksum_fixup;
168 struct netfront_rx_info {
169 struct xen_netif_rx_response rx;
170 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
174 * Access macros for acquiring freeing slots in tx_skbs[].
177 static void add_id_to_list(unsigned *head, unsigned short *list,
184 static unsigned short get_id_from_list(unsigned *head, unsigned short *list)
186 unsigned int id = *head;
188 if (id != TX_LINK_NONE) {
190 list[id] = TX_LINK_NONE;
195 static int xennet_rxidx(RING_IDX idx)
197 return idx & (NET_RX_RING_SIZE - 1);
200 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
203 int i = xennet_rxidx(ri);
204 struct sk_buff *skb = queue->rx_skbs[i];
205 queue->rx_skbs[i] = NULL;
209 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
212 int i = xennet_rxidx(ri);
213 grant_ref_t ref = queue->grant_rx_ref[i];
214 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
219 static const struct attribute_group xennet_dev_group;
222 static bool xennet_can_sg(struct net_device *dev)
224 return dev->features & NETIF_F_SG;
228 static void rx_refill_timeout(unsigned long data)
230 struct netfront_queue *queue = (struct netfront_queue *)data;
231 napi_schedule(&queue->napi);
234 static int netfront_tx_slot_available(struct netfront_queue *queue)
236 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
237 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
240 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
242 struct net_device *dev = queue->info->netdev;
243 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
245 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
246 netfront_tx_slot_available(queue) &&
247 likely(netif_running(dev)))
248 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
252 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
257 skb = __netdev_alloc_skb(queue->info->netdev,
258 RX_COPY_THRESHOLD + NET_IP_ALIGN,
259 GFP_ATOMIC | __GFP_NOWARN);
263 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
268 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
270 /* Align ip header to a 16 bytes boundary */
271 skb_reserve(skb, NET_IP_ALIGN);
272 skb->dev = queue->info->netdev;
278 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
280 RING_IDX req_prod = queue->rx.req_prod_pvt;
284 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
287 for (req_prod = queue->rx.req_prod_pvt;
288 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
294 struct xen_netif_rx_request *req;
296 skb = xennet_alloc_one_rx_buffer(queue);
302 id = xennet_rxidx(req_prod);
304 BUG_ON(queue->rx_skbs[id]);
305 queue->rx_skbs[id] = skb;
307 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
308 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
309 queue->grant_rx_ref[id] = ref;
311 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
313 req = RING_GET_REQUEST(&queue->rx, req_prod);
314 gnttab_page_grant_foreign_access_ref_one(ref,
315 queue->info->xbdev->otherend_id,
322 queue->rx.req_prod_pvt = req_prod;
324 /* Try again later if there are not enough requests or skb allocation
326 * Enough requests is quantified as the sum of newly created slots and
327 * the unconsumed slots at the backend.
329 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
331 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
335 wmb(); /* barrier so backend seens requests */
337 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
339 notify_remote_via_irq(queue->rx_irq);
342 static int xennet_open(struct net_device *dev)
344 struct netfront_info *np = netdev_priv(dev);
345 unsigned int num_queues = dev->real_num_tx_queues;
347 struct netfront_queue *queue = NULL;
349 if (!np->queues || np->broken)
352 for (i = 0; i < num_queues; ++i) {
353 queue = &np->queues[i];
354 napi_enable(&queue->napi);
356 spin_lock_bh(&queue->rx_lock);
357 if (netif_carrier_ok(dev)) {
358 xennet_alloc_rx_buffers(queue);
359 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
360 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
361 napi_schedule(&queue->napi);
363 spin_unlock_bh(&queue->rx_lock);
366 netif_tx_start_all_queues(dev);
371 static bool xennet_tx_buf_gc(struct netfront_queue *queue)
377 bool work_done = false;
378 const struct device *dev = &queue->info->netdev->dev;
380 BUG_ON(!netif_carrier_ok(queue->info->netdev));
383 prod = queue->tx.sring->rsp_prod;
384 if (RING_RESPONSE_PROD_OVERFLOW(&queue->tx, prod)) {
385 dev_alert(dev, "Illegal number of responses %u\n",
386 prod - queue->tx.rsp_cons);
389 rmb(); /* Ensure we see responses up to 'rp'. */
391 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
392 struct xen_netif_tx_response txrsp;
396 RING_COPY_RESPONSE(&queue->tx, cons, &txrsp);
397 if (txrsp.status == XEN_NETIF_RSP_NULL)
401 if (id >= RING_SIZE(&queue->tx)) {
403 "Response has incorrect id (%u)\n",
407 if (queue->tx_link[id] != TX_PENDING) {
409 "Response for inactive request\n");
413 queue->tx_link[id] = TX_LINK_NONE;
414 skb = queue->tx_skbs[id];
415 queue->tx_skbs[id] = NULL;
416 if (unlikely(!gnttab_end_foreign_access_ref(
417 queue->grant_tx_ref[id], GNTMAP_readonly))) {
419 "Grant still in use by backend domain\n");
422 gnttab_release_grant_reference(
423 &queue->gref_tx_head, queue->grant_tx_ref[id]);
424 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
425 queue->grant_tx_page[id] = NULL;
426 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, id);
427 dev_kfree_skb_irq(skb);
430 queue->tx.rsp_cons = prod;
432 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
433 } while (more_to_do);
435 xennet_maybe_wake_tx(queue);
440 queue->info->broken = true;
441 dev_alert(dev, "Disabled for further use\n");
446 struct xennet_gnttab_make_txreq {
447 struct netfront_queue *queue;
450 struct xen_netif_tx_request *tx; /* Last request on ring page */
451 struct xen_netif_tx_request tx_local; /* Last request local copy*/
455 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
456 unsigned int len, void *data)
458 struct xennet_gnttab_make_txreq *info = data;
460 struct xen_netif_tx_request *tx;
462 /* convenient aliases */
463 struct page *page = info->page;
464 struct netfront_queue *queue = info->queue;
465 struct sk_buff *skb = info->skb;
467 id = get_id_from_list(&queue->tx_skb_freelist, queue->tx_link);
468 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
469 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
470 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
472 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
473 gfn, GNTMAP_readonly);
475 queue->tx_skbs[id] = skb;
476 queue->grant_tx_page[id] = page;
477 queue->grant_tx_ref[id] = ref;
479 info->tx_local.id = id;
480 info->tx_local.gref = ref;
481 info->tx_local.offset = offset;
482 info->tx_local.size = len;
483 info->tx_local.flags = 0;
485 *tx = info->tx_local;
488 * Put the request in the pending queue, it will be set to be pending
489 * when the producer index is about to be raised.
491 add_id_to_list(&queue->tx_pend_queue, queue->tx_link, id);
494 info->size += info->tx_local.size;
497 static struct xen_netif_tx_request *xennet_make_first_txreq(
498 struct xennet_gnttab_make_txreq *info,
499 unsigned int offset, unsigned int len)
503 gnttab_for_one_grant(info->page, offset, len, xennet_tx_setup_grant, info);
508 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
509 unsigned int len, void *data)
511 struct xennet_gnttab_make_txreq *info = data;
513 info->tx->flags |= XEN_NETTXF_more_data;
515 xennet_tx_setup_grant(gfn, offset, len, data);
518 static void xennet_make_txreqs(
519 struct xennet_gnttab_make_txreq *info,
521 unsigned int offset, unsigned int len)
523 /* Skip unused frames from start of page */
524 page += offset >> PAGE_SHIFT;
525 offset &= ~PAGE_MASK;
531 gnttab_foreach_grant_in_range(page, offset, len,
532 xennet_make_one_txreq,
542 * Count how many ring slots are required to send this skb. Each frag
543 * might be a compound page.
545 static int xennet_count_skb_slots(struct sk_buff *skb)
547 int i, frags = skb_shinfo(skb)->nr_frags;
550 slots = gnttab_count_grant(offset_in_page(skb->data),
553 for (i = 0; i < frags; i++) {
554 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
555 unsigned long size = skb_frag_size(frag);
556 unsigned long offset = frag->page_offset;
558 /* Skip unused frames from start of page */
559 offset &= ~PAGE_MASK;
561 slots += gnttab_count_grant(offset, size);
567 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
568 void *accel_priv, select_queue_fallback_t fallback)
570 unsigned int num_queues = dev->real_num_tx_queues;
574 /* First, check if there is only one queue */
575 if (num_queues == 1) {
578 hash = skb_get_hash(skb);
579 queue_idx = hash % num_queues;
585 static void xennet_mark_tx_pending(struct netfront_queue *queue)
589 while ((i = get_id_from_list(&queue->tx_pend_queue, queue->tx_link)) !=
591 queue->tx_link[i] = TX_PENDING;
594 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
596 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
598 struct netfront_info *np = netdev_priv(dev);
599 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
600 struct xen_netif_tx_request *first_tx;
608 struct netfront_queue *queue = NULL;
609 struct xennet_gnttab_make_txreq info = { };
610 unsigned int num_queues = dev->real_num_tx_queues;
612 struct sk_buff *nskb;
614 /* Drop the packet if no queues are set up */
617 if (unlikely(np->broken))
619 /* Determine which queue to transmit this SKB on */
620 queue_index = skb_get_queue_mapping(skb);
621 queue = &np->queues[queue_index];
623 /* If skb->len is too big for wire format, drop skb and alert
624 * user about misconfiguration.
626 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
627 net_alert_ratelimited(
628 "xennet: skb->len = %u, too big for wire format\n",
633 slots = xennet_count_skb_slots(skb);
634 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
635 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
637 if (skb_linearize(skb))
641 page = virt_to_page(skb->data);
642 offset = offset_in_page(skb->data);
644 /* The first req should be at least ETH_HLEN size or the packet will be
645 * dropped by netback.
647 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
648 nskb = skb_copy(skb, GFP_ATOMIC);
651 dev_kfree_skb_any(skb);
653 page = virt_to_page(skb->data);
654 offset = offset_in_page(skb->data);
657 len = skb_headlen(skb);
659 spin_lock_irqsave(&queue->tx_lock, flags);
661 if (unlikely(!netif_carrier_ok(dev) ||
662 (slots > 1 && !xennet_can_sg(dev)) ||
663 netif_needs_gso(skb, netif_skb_features(skb)))) {
664 spin_unlock_irqrestore(&queue->tx_lock, flags);
668 /* First request for the linear area. */
672 first_tx = xennet_make_first_txreq(&info, offset, len);
673 offset += info.tx_local.size;
674 if (offset == PAGE_SIZE) {
678 len -= info.tx_local.size;
680 if (skb->ip_summed == CHECKSUM_PARTIAL)
682 first_tx->flags |= XEN_NETTXF_csum_blank |
683 XEN_NETTXF_data_validated;
684 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
685 /* remote but checksummed. */
686 first_tx->flags |= XEN_NETTXF_data_validated;
688 /* Optional extra info after the first request. */
689 if (skb_shinfo(skb)->gso_size) {
690 struct xen_netif_extra_info *gso;
692 gso = (struct xen_netif_extra_info *)
693 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
695 first_tx->flags |= XEN_NETTXF_extra_info;
697 gso->u.gso.size = skb_shinfo(skb)->gso_size;
698 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
699 XEN_NETIF_GSO_TYPE_TCPV6 :
700 XEN_NETIF_GSO_TYPE_TCPV4;
702 gso->u.gso.features = 0;
704 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
708 /* Requests for the rest of the linear area. */
709 xennet_make_txreqs(&info, page, offset, len);
711 /* Requests for all the frags. */
712 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
713 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
714 xennet_make_txreqs(&info, skb_frag_page(frag),
716 skb_frag_size(frag));
719 /* First request has the packet length. */
720 first_tx->size = skb->len;
722 xennet_mark_tx_pending(queue);
724 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
726 notify_remote_via_irq(queue->tx_irq);
728 u64_stats_update_begin(&tx_stats->syncp);
729 tx_stats->bytes += skb->len;
731 u64_stats_update_end(&tx_stats->syncp);
733 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
734 xennet_tx_buf_gc(queue);
736 if (!netfront_tx_slot_available(queue))
737 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
739 spin_unlock_irqrestore(&queue->tx_lock, flags);
744 dev->stats.tx_dropped++;
745 dev_kfree_skb_any(skb);
749 static int xennet_close(struct net_device *dev)
751 struct netfront_info *np = netdev_priv(dev);
752 unsigned int num_queues = dev->real_num_tx_queues;
754 struct netfront_queue *queue;
755 netif_tx_stop_all_queues(np->netdev);
756 for (i = 0; i < num_queues; ++i) {
757 queue = &np->queues[i];
758 napi_disable(&queue->napi);
763 static void xennet_set_rx_rsp_cons(struct netfront_queue *queue, RING_IDX val)
767 spin_lock_irqsave(&queue->rx_cons_lock, flags);
768 queue->rx.rsp_cons = val;
769 queue->rx_rsp_unconsumed = RING_HAS_UNCONSUMED_RESPONSES(&queue->rx);
770 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
773 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
776 int new = xennet_rxidx(queue->rx.req_prod_pvt);
778 BUG_ON(queue->rx_skbs[new]);
779 queue->rx_skbs[new] = skb;
780 queue->grant_rx_ref[new] = ref;
781 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
782 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
783 queue->rx.req_prod_pvt++;
786 static int xennet_get_extras(struct netfront_queue *queue,
787 struct xen_netif_extra_info *extras,
791 struct xen_netif_extra_info extra;
792 struct device *dev = &queue->info->netdev->dev;
793 RING_IDX cons = queue->rx.rsp_cons;
800 if (unlikely(cons + 1 == rp)) {
802 dev_warn(dev, "Missing extra info\n");
807 RING_COPY_RESPONSE(&queue->rx, ++cons, &extra);
809 if (unlikely(!extra.type ||
810 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
812 dev_warn(dev, "Invalid extra type: %d\n",
816 extras[extra.type - 1] = extra;
819 skb = xennet_get_rx_skb(queue, cons);
820 ref = xennet_get_rx_ref(queue, cons);
821 xennet_move_rx_slot(queue, skb, ref);
822 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
824 xennet_set_rx_rsp_cons(queue, cons);
828 static int xennet_get_responses(struct netfront_queue *queue,
829 struct netfront_rx_info *rinfo, RING_IDX rp,
830 struct sk_buff_head *list)
832 struct xen_netif_rx_response *rx = &rinfo->rx, rx_local;
833 struct xen_netif_extra_info *extras = rinfo->extras;
834 struct device *dev = &queue->info->netdev->dev;
835 RING_IDX cons = queue->rx.rsp_cons;
836 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
837 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
838 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
842 if (rx->flags & XEN_NETRXF_extra_info) {
843 err = xennet_get_extras(queue, extras, rp);
844 cons = queue->rx.rsp_cons;
848 if (unlikely(rx->status < 0 ||
849 rx->offset + rx->status > XEN_PAGE_SIZE)) {
851 dev_warn(dev, "rx->offset: %u, size: %d\n",
852 rx->offset, rx->status);
853 xennet_move_rx_slot(queue, skb, ref);
859 * This definitely indicates a bug, either in this driver or in
860 * the backend driver. In future this should flag the bad
861 * situation to the system controller to reboot the backend.
863 if (ref == GRANT_INVALID_REF) {
865 dev_warn(dev, "Bad rx response id %d.\n",
871 if (!gnttab_end_foreign_access_ref(ref, 0)) {
873 "Grant still in use by backend domain\n");
874 queue->info->broken = true;
875 dev_alert(dev, "Disabled for further use\n");
879 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
881 __skb_queue_tail(list, skb);
884 if (!(rx->flags & XEN_NETRXF_more_data))
887 if (cons + slots == rp) {
889 dev_warn(dev, "Need more slots\n");
894 RING_COPY_RESPONSE(&queue->rx, cons + slots, &rx_local);
896 skb = xennet_get_rx_skb(queue, cons + slots);
897 ref = xennet_get_rx_ref(queue, cons + slots);
901 if (unlikely(slots > max)) {
903 dev_warn(dev, "Too many slots\n");
908 xennet_set_rx_rsp_cons(queue, cons + slots);
913 static int xennet_set_skb_gso(struct sk_buff *skb,
914 struct xen_netif_extra_info *gso)
916 if (!gso->u.gso.size) {
918 pr_warn("GSO size must not be zero\n");
922 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
923 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
925 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
929 skb_shinfo(skb)->gso_size = gso->u.gso.size;
930 skb_shinfo(skb)->gso_type =
931 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
935 /* Header must be checked, and gso_segs computed. */
936 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
937 skb_shinfo(skb)->gso_segs = 0;
942 static int xennet_fill_frags(struct netfront_queue *queue,
944 struct sk_buff_head *list)
946 RING_IDX cons = queue->rx.rsp_cons;
947 struct sk_buff *nskb;
949 while ((nskb = __skb_dequeue(list))) {
950 struct xen_netif_rx_response rx;
951 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
953 RING_COPY_RESPONSE(&queue->rx, ++cons, &rx);
955 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) {
956 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
958 BUG_ON(pull_to < skb_headlen(skb));
959 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
961 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
962 xennet_set_rx_rsp_cons(queue,
963 ++cons + skb_queue_len(list));
968 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
969 skb_frag_page(nfrag),
970 rx.offset, rx.status, PAGE_SIZE);
972 skb_shinfo(nskb)->nr_frags = 0;
976 xennet_set_rx_rsp_cons(queue, cons);
981 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
983 bool recalculate_partial_csum = false;
986 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
987 * peers can fail to set NETRXF_csum_blank when sending a GSO
988 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
989 * recalculate the partial checksum.
991 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
992 struct netfront_info *np = netdev_priv(dev);
993 atomic_inc(&np->rx_gso_checksum_fixup);
994 skb->ip_summed = CHECKSUM_PARTIAL;
995 recalculate_partial_csum = true;
998 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
999 if (skb->ip_summed != CHECKSUM_PARTIAL)
1002 return skb_checksum_setup(skb, recalculate_partial_csum);
1005 static int handle_incoming_queue(struct netfront_queue *queue,
1006 struct sk_buff_head *rxq)
1008 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
1009 int packets_dropped = 0;
1010 struct sk_buff *skb;
1012 while ((skb = __skb_dequeue(rxq)) != NULL) {
1013 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1015 if (pull_to > skb_headlen(skb))
1016 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1018 /* Ethernet work: Delayed to here as it peeks the header. */
1019 skb->protocol = eth_type_trans(skb, queue->info->netdev);
1020 skb_reset_network_header(skb);
1022 if (checksum_setup(queue->info->netdev, skb)) {
1025 queue->info->netdev->stats.rx_errors++;
1029 u64_stats_update_begin(&rx_stats->syncp);
1030 rx_stats->packets++;
1031 rx_stats->bytes += skb->len;
1032 u64_stats_update_end(&rx_stats->syncp);
1035 napi_gro_receive(&queue->napi, skb);
1038 return packets_dropped;
1041 static int xennet_poll(struct napi_struct *napi, int budget)
1043 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
1044 struct net_device *dev = queue->info->netdev;
1045 struct sk_buff *skb;
1046 struct netfront_rx_info rinfo;
1047 struct xen_netif_rx_response *rx = &rinfo.rx;
1048 struct xen_netif_extra_info *extras = rinfo.extras;
1051 struct sk_buff_head rxq;
1052 struct sk_buff_head errq;
1053 struct sk_buff_head tmpq;
1056 spin_lock(&queue->rx_lock);
1058 skb_queue_head_init(&rxq);
1059 skb_queue_head_init(&errq);
1060 skb_queue_head_init(&tmpq);
1062 rp = queue->rx.sring->rsp_prod;
1063 if (RING_RESPONSE_PROD_OVERFLOW(&queue->rx, rp)) {
1064 dev_alert(&dev->dev, "Illegal number of responses %u\n",
1065 rp - queue->rx.rsp_cons);
1066 queue->info->broken = true;
1067 spin_unlock(&queue->rx_lock);
1070 rmb(); /* Ensure we see queued responses up to 'rp'. */
1072 i = queue->rx.rsp_cons;
1074 while ((i != rp) && (work_done < budget)) {
1075 RING_COPY_RESPONSE(&queue->rx, i, rx);
1076 memset(extras, 0, sizeof(rinfo.extras));
1078 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1080 if (unlikely(err)) {
1081 if (queue->info->broken) {
1082 spin_unlock(&queue->rx_lock);
1086 while ((skb = __skb_dequeue(&tmpq)))
1087 __skb_queue_tail(&errq, skb);
1088 dev->stats.rx_errors++;
1089 i = queue->rx.rsp_cons;
1093 skb = __skb_dequeue(&tmpq);
1095 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1096 struct xen_netif_extra_info *gso;
1097 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1099 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1100 __skb_queue_head(&tmpq, skb);
1101 xennet_set_rx_rsp_cons(queue,
1102 queue->rx.rsp_cons +
1103 skb_queue_len(&tmpq));
1108 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1109 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1110 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1112 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1113 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1114 skb->data_len = rx->status;
1115 skb->len += rx->status;
1117 if (unlikely(xennet_fill_frags(queue, skb, &tmpq)))
1120 if (rx->flags & XEN_NETRXF_csum_blank)
1121 skb->ip_summed = CHECKSUM_PARTIAL;
1122 else if (rx->flags & XEN_NETRXF_data_validated)
1123 skb->ip_summed = CHECKSUM_UNNECESSARY;
1125 __skb_queue_tail(&rxq, skb);
1127 i = queue->rx.rsp_cons + 1;
1128 xennet_set_rx_rsp_cons(queue, i);
1132 __skb_queue_purge(&errq);
1134 work_done -= handle_incoming_queue(queue, &rxq);
1136 xennet_alloc_rx_buffers(queue);
1138 if (work_done < budget) {
1141 napi_complete(napi);
1143 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1145 napi_schedule(napi);
1148 spin_unlock(&queue->rx_lock);
1153 static int xennet_change_mtu(struct net_device *dev, int mtu)
1155 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1163 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1164 struct rtnl_link_stats64 *tot)
1166 struct netfront_info *np = netdev_priv(dev);
1169 for_each_possible_cpu(cpu) {
1170 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1171 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1172 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1176 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1177 tx_packets = tx_stats->packets;
1178 tx_bytes = tx_stats->bytes;
1179 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1182 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1183 rx_packets = rx_stats->packets;
1184 rx_bytes = rx_stats->bytes;
1185 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1187 tot->rx_packets += rx_packets;
1188 tot->tx_packets += tx_packets;
1189 tot->rx_bytes += rx_bytes;
1190 tot->tx_bytes += tx_bytes;
1193 tot->rx_errors = dev->stats.rx_errors;
1194 tot->tx_dropped = dev->stats.tx_dropped;
1199 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1201 struct sk_buff *skb;
1204 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1205 /* Skip over entries which are actually freelist references */
1206 if (!queue->tx_skbs[i])
1209 skb = queue->tx_skbs[i];
1210 queue->tx_skbs[i] = NULL;
1211 get_page(queue->grant_tx_page[i]);
1212 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1214 (unsigned long)page_address(queue->grant_tx_page[i]));
1215 queue->grant_tx_page[i] = NULL;
1216 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1217 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, i);
1218 dev_kfree_skb_irq(skb);
1222 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1226 spin_lock_bh(&queue->rx_lock);
1228 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1229 struct sk_buff *skb;
1232 skb = queue->rx_skbs[id];
1236 ref = queue->grant_rx_ref[id];
1237 if (ref == GRANT_INVALID_REF)
1240 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1242 /* gnttab_end_foreign_access() needs a page ref until
1243 * foreign access is ended (which may be deferred).
1246 gnttab_end_foreign_access(ref, 0,
1247 (unsigned long)page_address(page));
1248 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1253 spin_unlock_bh(&queue->rx_lock);
1256 static netdev_features_t xennet_fix_features(struct net_device *dev,
1257 netdev_features_t features)
1259 struct netfront_info *np = netdev_priv(dev);
1262 if (features & NETIF_F_SG) {
1263 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1268 features &= ~NETIF_F_SG;
1271 if (features & NETIF_F_IPV6_CSUM) {
1272 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1273 "feature-ipv6-csum-offload", "%d", &val) < 0)
1277 features &= ~NETIF_F_IPV6_CSUM;
1280 if (features & NETIF_F_TSO) {
1281 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1282 "feature-gso-tcpv4", "%d", &val) < 0)
1286 features &= ~NETIF_F_TSO;
1289 if (features & NETIF_F_TSO6) {
1290 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1291 "feature-gso-tcpv6", "%d", &val) < 0)
1295 features &= ~NETIF_F_TSO6;
1301 static int xennet_set_features(struct net_device *dev,
1302 netdev_features_t features)
1304 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1305 netdev_info(dev, "Reducing MTU because no SG offload");
1306 dev->mtu = ETH_DATA_LEN;
1312 static bool xennet_handle_tx(struct netfront_queue *queue, unsigned int *eoi)
1314 unsigned long flags;
1316 if (unlikely(queue->info->broken))
1319 spin_lock_irqsave(&queue->tx_lock, flags);
1320 if (xennet_tx_buf_gc(queue))
1322 spin_unlock_irqrestore(&queue->tx_lock, flags);
1327 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1329 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1331 if (likely(xennet_handle_tx(dev_id, &eoiflag)))
1332 xen_irq_lateeoi(irq, eoiflag);
1337 static bool xennet_handle_rx(struct netfront_queue *queue, unsigned int *eoi)
1339 unsigned int work_queued;
1340 unsigned long flags;
1342 if (unlikely(queue->info->broken))
1345 spin_lock_irqsave(&queue->rx_cons_lock, flags);
1346 work_queued = RING_HAS_UNCONSUMED_RESPONSES(&queue->rx);
1347 if (work_queued > queue->rx_rsp_unconsumed) {
1348 queue->rx_rsp_unconsumed = work_queued;
1350 } else if (unlikely(work_queued < queue->rx_rsp_unconsumed)) {
1351 const struct device *dev = &queue->info->netdev->dev;
1353 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1354 dev_alert(dev, "RX producer index going backwards\n");
1355 dev_alert(dev, "Disabled for further use\n");
1356 queue->info->broken = true;
1359 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1361 if (likely(netif_carrier_ok(queue->info->netdev) && work_queued))
1362 napi_schedule(&queue->napi);
1367 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1369 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1371 if (likely(xennet_handle_rx(dev_id, &eoiflag)))
1372 xen_irq_lateeoi(irq, eoiflag);
1377 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1379 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1381 if (xennet_handle_tx(dev_id, &eoiflag) &&
1382 xennet_handle_rx(dev_id, &eoiflag))
1383 xen_irq_lateeoi(irq, eoiflag);
1388 #ifdef CONFIG_NET_POLL_CONTROLLER
1389 static void xennet_poll_controller(struct net_device *dev)
1391 /* Poll each queue */
1392 struct netfront_info *info = netdev_priv(dev);
1393 unsigned int num_queues = dev->real_num_tx_queues;
1399 for (i = 0; i < num_queues; ++i)
1400 xennet_interrupt(0, &info->queues[i]);
1404 static const struct net_device_ops xennet_netdev_ops = {
1405 .ndo_open = xennet_open,
1406 .ndo_stop = xennet_close,
1407 .ndo_start_xmit = xennet_start_xmit,
1408 .ndo_change_mtu = xennet_change_mtu,
1409 .ndo_get_stats64 = xennet_get_stats64,
1410 .ndo_set_mac_address = eth_mac_addr,
1411 .ndo_validate_addr = eth_validate_addr,
1412 .ndo_fix_features = xennet_fix_features,
1413 .ndo_set_features = xennet_set_features,
1414 .ndo_select_queue = xennet_select_queue,
1415 #ifdef CONFIG_NET_POLL_CONTROLLER
1416 .ndo_poll_controller = xennet_poll_controller,
1420 static void xennet_free_netdev(struct net_device *netdev)
1422 struct netfront_info *np = netdev_priv(netdev);
1424 free_percpu(np->rx_stats);
1425 free_percpu(np->tx_stats);
1426 free_netdev(netdev);
1429 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1432 struct net_device *netdev;
1433 struct netfront_info *np;
1435 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1437 return ERR_PTR(-ENOMEM);
1439 np = netdev_priv(netdev);
1445 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1446 if (np->rx_stats == NULL)
1448 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1449 if (np->tx_stats == NULL)
1452 netdev->netdev_ops = &xennet_netdev_ops;
1454 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1456 netdev->hw_features = NETIF_F_SG |
1458 NETIF_F_TSO | NETIF_F_TSO6;
1461 * Assume that all hw features are available for now. This set
1462 * will be adjusted by the call to netdev_update_features() in
1463 * xennet_connect() which is the earliest point where we can
1464 * negotiate with the backend regarding supported features.
1466 netdev->features |= netdev->hw_features;
1468 netdev->ethtool_ops = &xennet_ethtool_ops;
1469 SET_NETDEV_DEV(netdev, &dev->dev);
1471 np->netdev = netdev;
1473 netif_carrier_off(netdev);
1476 xenbus_switch_state(dev, XenbusStateInitialising);
1477 err = wait_event_timeout(module_wq,
1478 xenbus_read_driver_state(dev->otherend) !=
1479 XenbusStateClosed &&
1480 xenbus_read_driver_state(dev->otherend) !=
1481 XenbusStateUnknown, XENNET_TIMEOUT);
1487 xennet_free_netdev(netdev);
1488 return ERR_PTR(err);
1492 * Entry point to this code when a new device is created. Allocate the basic
1493 * structures and the ring buffers for communication with the backend, and
1494 * inform the backend of the appropriate details for those.
1496 static int netfront_probe(struct xenbus_device *dev,
1497 const struct xenbus_device_id *id)
1500 struct net_device *netdev;
1501 struct netfront_info *info;
1503 netdev = xennet_create_dev(dev);
1504 if (IS_ERR(netdev)) {
1505 err = PTR_ERR(netdev);
1506 xenbus_dev_fatal(dev, err, "creating netdev");
1510 info = netdev_priv(netdev);
1511 dev_set_drvdata(&dev->dev, info);
1513 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1519 static void xennet_end_access(int ref, void *page)
1521 /* This frees the page as a side-effect */
1522 if (ref != GRANT_INVALID_REF)
1523 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1526 static void xennet_disconnect_backend(struct netfront_info *info)
1529 unsigned int num_queues = info->netdev->real_num_tx_queues;
1531 netif_carrier_off(info->netdev);
1533 for (i = 0; i < num_queues && info->queues; ++i) {
1534 struct netfront_queue *queue = &info->queues[i];
1536 del_timer_sync(&queue->rx_refill_timer);
1538 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1539 unbind_from_irqhandler(queue->tx_irq, queue);
1540 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1541 unbind_from_irqhandler(queue->tx_irq, queue);
1542 unbind_from_irqhandler(queue->rx_irq, queue);
1544 queue->tx_evtchn = queue->rx_evtchn = 0;
1545 queue->tx_irq = queue->rx_irq = 0;
1547 if (netif_running(info->netdev))
1548 napi_synchronize(&queue->napi);
1550 xennet_release_tx_bufs(queue);
1551 xennet_release_rx_bufs(queue);
1552 gnttab_free_grant_references(queue->gref_tx_head);
1553 gnttab_free_grant_references(queue->gref_rx_head);
1555 /* End access and free the pages */
1556 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1557 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1559 queue->tx_ring_ref = GRANT_INVALID_REF;
1560 queue->rx_ring_ref = GRANT_INVALID_REF;
1561 queue->tx.sring = NULL;
1562 queue->rx.sring = NULL;
1567 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1568 * driver restart. We tear down our netif structure and recreate it, but
1569 * leave the device-layer structures intact so that this is transparent to the
1570 * rest of the kernel.
1572 static int netfront_resume(struct xenbus_device *dev)
1574 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1576 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1578 netif_tx_lock_bh(info->netdev);
1579 netif_device_detach(info->netdev);
1580 netif_tx_unlock_bh(info->netdev);
1582 xennet_disconnect_backend(info);
1586 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1588 char *s, *e, *macstr;
1591 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1593 return PTR_ERR(macstr);
1595 for (i = 0; i < ETH_ALEN; i++) {
1596 mac[i] = simple_strtoul(s, &e, 16);
1597 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1608 static int setup_netfront_single(struct netfront_queue *queue)
1612 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1616 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1617 xennet_interrupt, 0,
1618 queue->info->netdev->name,
1622 queue->rx_evtchn = queue->tx_evtchn;
1623 queue->rx_irq = queue->tx_irq = err;
1628 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1629 queue->tx_evtchn = 0;
1634 static int setup_netfront_split(struct netfront_queue *queue)
1638 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1641 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1643 goto alloc_rx_evtchn_fail;
1645 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1646 "%s-tx", queue->name);
1647 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1648 xennet_tx_interrupt, 0,
1649 queue->tx_irq_name, queue);
1652 queue->tx_irq = err;
1654 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1655 "%s-rx", queue->name);
1656 err = bind_evtchn_to_irqhandler_lateeoi(queue->rx_evtchn,
1657 xennet_rx_interrupt, 0,
1658 queue->rx_irq_name, queue);
1661 queue->rx_irq = err;
1666 unbind_from_irqhandler(queue->tx_irq, queue);
1669 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1670 queue->rx_evtchn = 0;
1671 alloc_rx_evtchn_fail:
1672 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1673 queue->tx_evtchn = 0;
1678 static int setup_netfront(struct xenbus_device *dev,
1679 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1681 struct xen_netif_tx_sring *txs;
1682 struct xen_netif_rx_sring *rxs = NULL;
1686 queue->tx_ring_ref = GRANT_INVALID_REF;
1687 queue->rx_ring_ref = GRANT_INVALID_REF;
1688 queue->rx.sring = NULL;
1689 queue->tx.sring = NULL;
1691 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1694 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1697 SHARED_RING_INIT(txs);
1698 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1700 err = xenbus_grant_ring(dev, txs, 1, &gref);
1703 queue->tx_ring_ref = gref;
1705 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1708 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1711 SHARED_RING_INIT(rxs);
1712 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1714 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1717 queue->rx_ring_ref = gref;
1719 if (feature_split_evtchn)
1720 err = setup_netfront_split(queue);
1721 /* setup single event channel if
1722 * a) feature-split-event-channels == 0
1723 * b) feature-split-event-channels == 1 but failed to setup
1725 if (!feature_split_evtchn || (feature_split_evtchn && err))
1726 err = setup_netfront_single(queue);
1733 /* If we fail to setup netfront, it is safe to just revoke access to
1734 * granted pages because backend is not accessing it at this point.
1737 if (queue->rx_ring_ref != GRANT_INVALID_REF) {
1738 gnttab_end_foreign_access(queue->rx_ring_ref, 0,
1739 (unsigned long)rxs);
1740 queue->rx_ring_ref = GRANT_INVALID_REF;
1742 free_page((unsigned long)rxs);
1744 if (queue->tx_ring_ref != GRANT_INVALID_REF) {
1745 gnttab_end_foreign_access(queue->tx_ring_ref, 0,
1746 (unsigned long)txs);
1747 queue->tx_ring_ref = GRANT_INVALID_REF;
1749 free_page((unsigned long)txs);
1754 /* Queue-specific initialisation
1755 * This used to be done in xennet_create_dev() but must now
1758 static int xennet_init_queue(struct netfront_queue *queue)
1764 spin_lock_init(&queue->tx_lock);
1765 spin_lock_init(&queue->rx_lock);
1766 spin_lock_init(&queue->rx_cons_lock);
1768 setup_timer(&queue->rx_refill_timer, rx_refill_timeout,
1769 (unsigned long)queue);
1771 devid = strrchr(queue->info->xbdev->nodename, '/') + 1;
1772 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u",
1775 /* Initialise tx_skb_freelist as a free chain containing every entry. */
1776 queue->tx_skb_freelist = 0;
1777 queue->tx_pend_queue = TX_LINK_NONE;
1778 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1779 queue->tx_link[i] = i + 1;
1780 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1781 queue->grant_tx_page[i] = NULL;
1783 queue->tx_link[NET_TX_RING_SIZE - 1] = TX_LINK_NONE;
1785 /* Clear out rx_skbs */
1786 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1787 queue->rx_skbs[i] = NULL;
1788 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1791 /* A grant for every tx ring slot */
1792 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1793 &queue->gref_tx_head) < 0) {
1794 pr_alert("can't alloc tx grant refs\n");
1799 /* A grant for every rx ring slot */
1800 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1801 &queue->gref_rx_head) < 0) {
1802 pr_alert("can't alloc rx grant refs\n");
1810 gnttab_free_grant_references(queue->gref_tx_head);
1815 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1816 struct xenbus_transaction *xbt, int write_hierarchical)
1818 /* Write the queue-specific keys into XenStore in the traditional
1819 * way for a single queue, or in a queue subkeys for multiple
1822 struct xenbus_device *dev = queue->info->xbdev;
1824 const char *message;
1828 /* Choose the correct place to write the keys */
1829 if (write_hierarchical) {
1830 pathsize = strlen(dev->nodename) + 10;
1831 path = kzalloc(pathsize, GFP_KERNEL);
1834 message = "out of memory while writing ring references";
1837 snprintf(path, pathsize, "%s/queue-%u",
1838 dev->nodename, queue->id);
1840 path = (char *)dev->nodename;
1843 /* Write ring references */
1844 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1845 queue->tx_ring_ref);
1847 message = "writing tx-ring-ref";
1851 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1852 queue->rx_ring_ref);
1854 message = "writing rx-ring-ref";
1858 /* Write event channels; taking into account both shared
1859 * and split event channel scenarios.
1861 if (queue->tx_evtchn == queue->rx_evtchn) {
1862 /* Shared event channel */
1863 err = xenbus_printf(*xbt, path,
1864 "event-channel", "%u", queue->tx_evtchn);
1866 message = "writing event-channel";
1870 /* Split event channels */
1871 err = xenbus_printf(*xbt, path,
1872 "event-channel-tx", "%u", queue->tx_evtchn);
1874 message = "writing event-channel-tx";
1878 err = xenbus_printf(*xbt, path,
1879 "event-channel-rx", "%u", queue->rx_evtchn);
1881 message = "writing event-channel-rx";
1886 if (write_hierarchical)
1891 if (write_hierarchical)
1893 xenbus_dev_fatal(dev, err, "%s", message);
1897 static void xennet_destroy_queues(struct netfront_info *info)
1901 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1902 struct netfront_queue *queue = &info->queues[i];
1904 if (netif_running(info->netdev))
1905 napi_disable(&queue->napi);
1906 netif_napi_del(&queue->napi);
1909 kfree(info->queues);
1910 info->queues = NULL;
1913 static int xennet_create_queues(struct netfront_info *info,
1914 unsigned int *num_queues)
1919 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
1924 for (i = 0; i < *num_queues; i++) {
1925 struct netfront_queue *queue = &info->queues[i];
1930 ret = xennet_init_queue(queue);
1932 dev_warn(&info->xbdev->dev,
1933 "only created %d queues\n", i);
1938 netif_napi_add(queue->info->netdev, &queue->napi,
1940 if (netif_running(info->netdev))
1941 napi_enable(&queue->napi);
1944 netif_set_real_num_tx_queues(info->netdev, *num_queues);
1946 if (*num_queues == 0) {
1947 dev_err(&info->xbdev->dev, "no queues\n");
1953 /* Common code used when first setting up, and when resuming. */
1954 static int talk_to_netback(struct xenbus_device *dev,
1955 struct netfront_info *info)
1957 const char *message;
1958 struct xenbus_transaction xbt;
1960 unsigned int feature_split_evtchn;
1962 unsigned int max_queues = 0;
1963 struct netfront_queue *queue = NULL;
1964 unsigned int num_queues = 1;
1966 info->netdev->irq = 0;
1968 /* Check if backend supports multiple queues */
1969 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1970 "multi-queue-max-queues", "%u", &max_queues);
1973 num_queues = min(max_queues, xennet_max_queues);
1975 /* Check feature-split-event-channels */
1976 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1977 "feature-split-event-channels", "%u",
1978 &feature_split_evtchn);
1980 feature_split_evtchn = 0;
1982 /* Read mac addr. */
1983 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1985 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1991 xennet_destroy_queues(info);
1993 /* For the case of a reconnect reset the "broken" indicator. */
1994 info->broken = false;
1996 err = xennet_create_queues(info, &num_queues);
1998 xenbus_dev_fatal(dev, err, "creating queues");
1999 kfree(info->queues);
2000 info->queues = NULL;
2005 /* Create shared ring, alloc event channel -- for each queue */
2006 for (i = 0; i < num_queues; ++i) {
2007 queue = &info->queues[i];
2008 err = setup_netfront(dev, queue, feature_split_evtchn);
2014 err = xenbus_transaction_start(&xbt);
2016 xenbus_dev_fatal(dev, err, "starting transaction");
2020 if (xenbus_exists(XBT_NIL,
2021 info->xbdev->otherend, "multi-queue-max-queues")) {
2022 /* Write the number of queues */
2023 err = xenbus_printf(xbt, dev->nodename,
2024 "multi-queue-num-queues", "%u", num_queues);
2026 message = "writing multi-queue-num-queues";
2027 goto abort_transaction_no_dev_fatal;
2031 if (num_queues == 1) {
2032 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
2034 goto abort_transaction_no_dev_fatal;
2036 /* Write the keys for each queue */
2037 for (i = 0; i < num_queues; ++i) {
2038 queue = &info->queues[i];
2039 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
2041 goto abort_transaction_no_dev_fatal;
2045 /* The remaining keys are not queue-specific */
2046 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
2049 message = "writing request-rx-copy";
2050 goto abort_transaction;
2053 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
2055 message = "writing feature-rx-notify";
2056 goto abort_transaction;
2059 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
2061 message = "writing feature-sg";
2062 goto abort_transaction;
2065 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
2067 message = "writing feature-gso-tcpv4";
2068 goto abort_transaction;
2071 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
2073 message = "writing feature-gso-tcpv6";
2074 goto abort_transaction;
2077 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
2080 message = "writing feature-ipv6-csum-offload";
2081 goto abort_transaction;
2084 err = xenbus_transaction_end(xbt, 0);
2088 xenbus_dev_fatal(dev, err, "completing transaction");
2095 xenbus_dev_fatal(dev, err, "%s", message);
2096 abort_transaction_no_dev_fatal:
2097 xenbus_transaction_end(xbt, 1);
2099 xennet_disconnect_backend(info);
2101 xennet_destroy_queues(info);
2105 device_unregister(&dev->dev);
2109 static int xennet_connect(struct net_device *dev)
2111 struct netfront_info *np = netdev_priv(dev);
2112 unsigned int num_queues = 0;
2114 unsigned int feature_rx_copy;
2116 struct netfront_queue *queue = NULL;
2118 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
2119 "feature-rx-copy", "%u", &feature_rx_copy);
2121 feature_rx_copy = 0;
2123 if (!feature_rx_copy) {
2125 "backend does not support copying receive path\n");
2129 err = talk_to_netback(np->xbdev, np);
2133 /* talk_to_netback() sets the correct number of queues */
2134 num_queues = dev->real_num_tx_queues;
2136 if (dev->reg_state == NETREG_UNINITIALIZED) {
2137 err = register_netdev(dev);
2139 pr_warn("%s: register_netdev err=%d\n", __func__, err);
2140 device_unregister(&np->xbdev->dev);
2146 netdev_update_features(dev);
2150 * All public and private state should now be sane. Get
2151 * ready to start sending and receiving packets and give the driver
2152 * domain a kick because we've probably just requeued some
2155 netif_tx_lock_bh(np->netdev);
2156 netif_device_attach(np->netdev);
2157 netif_tx_unlock_bh(np->netdev);
2159 netif_carrier_on(np->netdev);
2160 for (j = 0; j < num_queues; ++j) {
2161 queue = &np->queues[j];
2163 notify_remote_via_irq(queue->tx_irq);
2164 if (queue->tx_irq != queue->rx_irq)
2165 notify_remote_via_irq(queue->rx_irq);
2167 spin_lock_irq(&queue->tx_lock);
2168 xennet_tx_buf_gc(queue);
2169 spin_unlock_irq(&queue->tx_lock);
2171 spin_lock_bh(&queue->rx_lock);
2172 xennet_alloc_rx_buffers(queue);
2173 spin_unlock_bh(&queue->rx_lock);
2180 * Callback received when the backend's state changes.
2182 static void netback_changed(struct xenbus_device *dev,
2183 enum xenbus_state backend_state)
2185 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2186 struct net_device *netdev = np->netdev;
2188 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2190 wake_up_all(&module_wq);
2192 switch (backend_state) {
2193 case XenbusStateInitialising:
2194 case XenbusStateInitialised:
2195 case XenbusStateReconfiguring:
2196 case XenbusStateReconfigured:
2197 case XenbusStateUnknown:
2200 case XenbusStateInitWait:
2201 if (dev->state != XenbusStateInitialising)
2203 if (xennet_connect(netdev) != 0)
2205 xenbus_switch_state(dev, XenbusStateConnected);
2208 case XenbusStateConnected:
2209 netdev_notify_peers(netdev);
2212 case XenbusStateClosed:
2213 if (dev->state == XenbusStateClosed)
2215 /* Missed the backend's CLOSING state -- fallthrough */
2216 case XenbusStateClosing:
2217 xenbus_frontend_closed(dev);
2222 static const struct xennet_stat {
2223 char name[ETH_GSTRING_LEN];
2225 } xennet_stats[] = {
2227 "rx_gso_checksum_fixup",
2228 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2232 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2234 switch (string_set) {
2236 return ARRAY_SIZE(xennet_stats);
2242 static void xennet_get_ethtool_stats(struct net_device *dev,
2243 struct ethtool_stats *stats, u64 * data)
2245 void *np = netdev_priv(dev);
2248 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2249 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2252 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2256 switch (stringset) {
2258 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2259 memcpy(data + i * ETH_GSTRING_LEN,
2260 xennet_stats[i].name, ETH_GSTRING_LEN);
2265 static const struct ethtool_ops xennet_ethtool_ops =
2267 .get_link = ethtool_op_get_link,
2269 .get_sset_count = xennet_get_sset_count,
2270 .get_ethtool_stats = xennet_get_ethtool_stats,
2271 .get_strings = xennet_get_strings,
2275 static ssize_t show_rxbuf(struct device *dev,
2276 struct device_attribute *attr, char *buf)
2278 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2281 static ssize_t store_rxbuf(struct device *dev,
2282 struct device_attribute *attr,
2283 const char *buf, size_t len)
2286 unsigned long target;
2288 if (!capable(CAP_NET_ADMIN))
2291 target = simple_strtoul(buf, &endp, 0);
2295 /* rxbuf_min and rxbuf_max are no longer configurable. */
2300 static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2301 static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2302 static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
2304 static struct attribute *xennet_dev_attrs[] = {
2305 &dev_attr_rxbuf_min.attr,
2306 &dev_attr_rxbuf_max.attr,
2307 &dev_attr_rxbuf_cur.attr,
2311 static const struct attribute_group xennet_dev_group = {
2312 .attrs = xennet_dev_attrs
2314 #endif /* CONFIG_SYSFS */
2316 static void xennet_bus_close(struct xenbus_device *dev)
2320 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2323 xenbus_switch_state(dev, XenbusStateClosing);
2324 ret = wait_event_timeout(module_wq,
2325 xenbus_read_driver_state(dev->otherend) ==
2326 XenbusStateClosing ||
2327 xenbus_read_driver_state(dev->otherend) ==
2328 XenbusStateClosed ||
2329 xenbus_read_driver_state(dev->otherend) ==
2334 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2338 xenbus_switch_state(dev, XenbusStateClosed);
2339 ret = wait_event_timeout(module_wq,
2340 xenbus_read_driver_state(dev->otherend) ==
2341 XenbusStateClosed ||
2342 xenbus_read_driver_state(dev->otherend) ==
2348 static int xennet_remove(struct xenbus_device *dev)
2350 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2352 xennet_bus_close(dev);
2353 xennet_disconnect_backend(info);
2355 if (info->netdev->reg_state == NETREG_REGISTERED)
2356 unregister_netdev(info->netdev);
2360 xennet_destroy_queues(info);
2363 xennet_free_netdev(info->netdev);
2368 static const struct xenbus_device_id netfront_ids[] = {
2373 static struct xenbus_driver netfront_driver = {
2374 .ids = netfront_ids,
2375 .probe = netfront_probe,
2376 .remove = xennet_remove,
2377 .resume = netfront_resume,
2378 .otherend_changed = netback_changed,
2381 static int __init netif_init(void)
2386 if (!xen_has_pv_nic_devices())
2389 pr_info("Initialising Xen virtual ethernet driver\n");
2391 /* Allow as many queues as there are CPUs if user has not
2392 * specified a value.
2394 if (xennet_max_queues == 0)
2395 xennet_max_queues = num_online_cpus();
2397 return xenbus_register_frontend(&netfront_driver);
2399 module_init(netif_init);
2402 static void __exit netif_exit(void)
2404 xenbus_unregister_driver(&netfront_driver);
2406 module_exit(netif_exit);
2408 MODULE_DESCRIPTION("Xen virtual network device frontend");
2409 MODULE_LICENSE("GPL");
2410 MODULE_ALIAS("xen:vif");
2411 MODULE_ALIAS("xennet");